Consuming media presentations generally involves listening to audio information and/or viewing video information such as, for example, radio programs, music, television programs, movies, still images, etc. Media-centric companies such as, for example, advertising companies, broadcasting networks, etc. are often interested in the viewing and listening interests of their audience to better allocate their advertising expenditures and better market their products.
A known technique often used to measure the exposure of audience members to media involves installing metering equipment within a household connected to one or more televisions and/or stereos throughout the household. When members of the household watch television or other video media content (e.g., digital video disks, video cassette recorders, persona video recorders, etc.) and/or listen to radio programming or audio from compact discs (CD's), tapes, etc., the metering equipment collects metering information (e.g., video or audio signatures (e.g., samples of the monitored signals or proxies representative of such samples), identification codes (e.g., codes ancillary to the program content inserted into the program for the purpose of audience measurement), time/date stamps, user identities, demographic characteristics, etc.).
Another known technique used to measure the exposure of audience members to media involves using personal portable metering devices (PPM's), which are also known as portable metering devices and portable personal meters. A PPM is an electronic device that is worn (e.g., clipped to a belt or other apparel) or otherwise carried by an audience member to monitor the media consumption (e.g., viewing and/or listening activities) of that audience member. To detect audio, some PPM's are provided with a microphone to pick up audio emitted from speakers (e.g., television speakers, stereo speakers, computer speakers, etc.). To detect video, some PPM's are provided with an optical sensor (e.g., a light sensor, a camera sensor, etc.) that picks up video emitted by a screen or display.